Orange County is demanding that GKN Aerospace, the company whose Garden Grove facility sparked a chemical crisis that prompted widespread evacuations across six cities, pay more than $4 million to cover costs stemming from the emergency.

The multimillion-dollar bill is meant to reimburse the county for costs incurred while dealing with the incident, which forced about 50,000 residents to flee as firefighters warned that a 7,000-gallon volatile chemical tank was at risk of exploding or causing a major spill.

In a letter sent Friday demanding payment, county attorneys called the May 21 incident a "catastrophic failure" of the company's chemical storage tank cooling system.

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"This incident was clearly not an unforeseeable accident as GKN has a well-documented history of regulatory violations at the site dating back over a decade," states the letter, which was obtained by The Times.

The company, according to county attorneys, faced California Division of Occupational Safety and Health citations and more than $900,000 in fines from the South Coast Air Quality Management District for past offenses.

GKN Aerospace officials did not respond to questions regarding the county's claim, but a spokesperson for the company said it was continuing to work with county officials on "next steps."

"We remain committed to the communities affected by the May incident and are continuing to explore appropriate next steps in the context of a complex legal environment," the spokesperson said in a statement. "We will continue to engage with County officials as well as numerous regulators and authorities as we reset the Garden Grove facility."

In May, a pressurized tank of methyl methacrylate began to fail at the company's facility in Garden Grove. The chemical in the tank continued to heat dangerously, and the cooling system at the facility was unable to reduce the temperature.

A crack was found in the tank, and fire officials said it was at risk of either leaking or exploding as internal pressure continued to build.

The incident has already prompted several inquiries, including by federal authorities. In June, the FBI served warrants at the facility. GKN officials at the time said they were cooperating with the investigation.

"The blame for this disaster lies solely with GKN and the county should not be bearing the brunt of these expenses," Orange County Supervisor Janet Nguyen said in a statement.

The letter to the company included an itemized list of costs incurred by county agencies during the emergency, including $2.7 million by the Orange County Sheriff's Department, more than $233,000 by the county executive office and $195,000 by the county's Health Care Agency. It also included $500,000 of discretionary funds that supervisors allocated to assist affected residents.

Additional expenses incurred by the Orange County Fire Authority — estimated at $2.8 million — were not included in the $4-million total.

"The county works hard to stay in excellent fiscal shape, and now we have 10 agencies with huge expenses along with OC Fire Authority," Nguyen said. "We need reimbursement."

Supervisor Donald Wagner, in a statement, said he expected GKN to repay the county for the costs.

"I think the claim on GKN is appropriate and I expect the company will promptly respond and make the county whole," Wagner said.

Supervisor Vicente Sarmiento said the incident was part of a larger problem of industrialization near residential neighborhoods, especially in communities of color.

"The company needs to be responsible and pay for the costs of the emergency response incurred to protect the community from the danger they created," Sarmiento said in a statement.

GKN had previously pledged more than $3 million to nonprofits, including the OC Community Resilience Fund launched by the United Way, to help residents and business owners.

But in the letter to GKN executives, the county argued that the donation did not absolve the company of liability or of costs incurred by taxpayers.

"The County demands immediate financial accountability to mitigate the impact caused to the County's public emergency resources," the letter states.

In the letter, county attorneys also requested that the company maintain all records, materials and physical evidence related to the incident because of possible future litigation.

This story originally appeared in Los Angeles Times.

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